A sample distribution system is known, for example, from U.S. Pat. No. 7,141,213 B1. A sample distribution system is used to prepare samples for an analysis or the like. In this process, for example, the samples are divided, centrifuged, mixed with test fluids, etc. In an inlet or loading area sample carriers, especially test tubes, are supplied to the system in so-called racks or sample holders. The supplying occurs, e.g., using drawer-type adjustable pan or drawer elements. In the sample distribution system, the racks can then be slid into specific positions and/or distributed to specific stations. It is also known here to place the rack on a so-called carriage, by which the rack can be driven into the system. Usually several racks next to each other and in rows are arranged on a pan or drawer, wherein the racks are arranged so that they are very closely adjacent to each other.
Providing receiving openings on an underside of the rack is known from U.S. Pat. No. 7,141,213 B1, by means of which the rack can be placed in movement on positioning pins of a carriage.
The object of the present invention is to produce a rack apparatus, wherein a rack can be connected quickly to a rack carriage and the connection can also be loosened without tools even when there is reduced available space.
This object is achieved by a rack apparatus for a sample distribution system comprising a rack with receivers for sample holders and a rack carriage, wherein the rack carriage and the rack are connected tightly to each other by a latching device that can be released without tools. This object is further achieved by a rack and/or a rack carriage for the rack apparatus according to the invention.
In the context of the invention, a tight connection is understood to mean a connection without degrees of freedom, wherein a slight play—e.g., due to manufacturing tolerances—may be present in individual directions. However, preferably there is a connection free from play. The latching device thus allows a fastening of the rack on the rack carriage without degrees of freedom, so the rack apparatus can be manipulated within the sample distribution system in any desired way with high accuracy. A tool-free loosening or connection of the two components is possible using a relative motion.
In one design of the invention, it is provided that the rack apparatus has latching elements complementary to each other arranged on the rack carriage and the rack, and at least one force element for application of a constraining force, whereby a latching connection can be produced or released by a relative motion between the rack carriage and the rack opposite the constraining force. Depending on the design of the latching elements, slight movements can already be adequate for loosening the connection. In one design, the relative motion is a translational motion. In other designs, rotation motions or combination motions are provided for loosening the connection. The required force for loosening preferably lies at 15 to 20 N.
In a further development of the invention, it is provided that the latching elements comprise latching bolts and latching grooves into which the latching bolts can be introduced. In one design, these latching bolts are arranged and dimensioned such that the latching bolts do not extend, or only extend insignificantly, from the rack device in the coupled state.
Preferably it is provided that the latching elements comprise at least one pair of latching bolts, comprising one rigid latching bolt and a movable latching bolt at a distance from it, whereby a distance of the latching bolt against the constraining force of the at least one force element can be changed. In this way, the latching bolts can be constrained into the latching grooves by the force element and held in the latching groove. In an advantageous design, the latching elements comprise at least one latching groove pair complementary to the latching bolt pair with at least two effective surfaces lying over each other, wherein the at least one force element constrains the latching bolt pair on the effective surfaces in a latched connection. The effective surfaces can be arranged so they are turned toward each other or away from each other. To connect, the rack is placed on the movable latching bolt and the latching bolt is slid until the latching groove assigned to the rigid latching bolt can be introduced into this latching bolt. The relative motion necessary for this is a combination motion.
In a further development, on opposite side surfaces of the rack carriage, a pair of latching bolts is provided, whereby the latching bolts are arranged at a distance from each other in the longitudinal direction. In the context of the invention, the longitudinal direction indicates an insertion direction of the rack apparatus into the sample distribution system. The rack and the rack carriage each have essentially rectangular base surfaces depending on their size. In this case, the lateral surfaces that run parallel to the longitudinal direction are designated as side surfaces. Preferably, a pair of latching grooves is provided on each side surface of the rack, in which a latching bolt pair engages for a latched connection. In an arrangement of this type, handling that is especially advantageous ergonomically is possible.
In another design of the invention, it is provided that inserts with elastic spring arms for holding the sample containers are inserted in the receivers. The elastic spring arms permit a good positioning of sample holders, especially of test tubes. Depending on the application, racks with inserts or without inserts, as well as mixed forms, are advantageous. The receivers preferably have a circular cross section. A diameter is, e.g., approx. 13.3 mm or approx. 16.5 mm.
In yet another design of the invention, it is provided that the rack is designed of unbreakable plastic, especially of polycarbonate, e.g., Lexan (CAS#25971-63-5).
In yet another design of the invention, it is provided that the rack is designed of an autoclavable plastic, especially of polycarbonate, e.g., Lexan (CAS#25971-63-5).
In a further development of the invention, it is provided that the rack is composed of an upper part and a lower part that is tightly connected to the upper part, especially welded or glued. Because of this, simple manufacturing is possible, for example using injection molding.
Preferably, it is provided that the lower part and the upper part have receivers arranged so they match each other for sample carriers, whereby the receivers of the lower part are designed so that they are narrowed conically. Because of the conical narrowing, test tubes with different diameters have to be held. The narrowing can occur continuously or in steps. The receivers preferably have a circular cross section.
In a further design of the invention, it is provided that the rack carriage is at least partially designed of a material that is magnetic and/or can be magnetized. In this way, the rack carriage can be coupled in a simple manner with different stations of the sample distribution system. For example, the rack carriage can be manufactured cost-effectively as a bent stamped part. In other designs, the rack carriage is made of a plastic.
In yet another design of the invention, it is provided that the rack carriage has coupling elements, especially positioning pins, for coupling with the sample distribution system. The coupling elements can be designed optionally. In their design, the coupling elements comprise a coding for recognition of a rack type.
Other advantages of the invention can be seen from the description below of exemplary embodiments of the invention, which are represented schematically in the drawings. For the same or similar components, uniform reference numbers are used in the drawings. Characteristics that are described or represented as part of an exemplary embodiment can also be used in a different exemplary embodiment in order to obtain an additional embodiment of the invention.